# -*- coding: utf-8 -*-

import re
from forum.models.user import User


def find_best_match_in_name(content, uname, fullname, start_index):
    uname = uname
    fullname = fullname

    end_index = start_index + len(fullname)

    while end_index > start_index:
        if content[start_index: end_index].lower() == fullname.lower():
            return content[start_index: end_index]

        while len(fullname) and fullname[-1] != ' ':
            fullname = fullname[:-1]

        fullname = fullname.rstrip()
        end_index = start_index + len(fullname)

    return uname


APPEAL_PATTERN = re.compile(r'(?<!\w)@\w+', re.UNICODE)


def auto_user_link(node, content):
    active_users = node.absolute_parent.get_active_users()

    appeals = APPEAL_PATTERN.finditer(content)

    replacements = []

    for appeal in appeals:
        # Try to find the profile URL
        username = appeal.group(0)[1:]

        matches = []

        for user in active_users:
            if user.username.lower().startswith(username.lower()):
                matches.append(user)

        if len(matches) == 1:
            replacements.append(
                (find_best_match_in_name(content, username, matches[0].username, appeal.start(0) + 1),
                 matches[0])
            )
        elif len(matches) == 0:
            matches = User.objects.filter(username__istartswith=username)

        if (len(matches) == 0):
            continue

        best_user_match = None
        final_match = ""

        for user in matches:
            user_match = find_best_match_in_name(content, username, user.username, appeal.start(0) + 1)

            if (len(user_match) < len(final_match)):
                continue

            if (len(user_match) == len(final_match)):
                if not (user.username.lower() == user_match.lower()):
                    continue

                if (best_user_match and (best_user_match.username == final_match)):
                    continue

            best_user_match = user
            final_match = user_match

        replacements.append((final_match, best_user_match))

    for replacement in replacements:
        to_replace = "@" + replacement[0]
        profile_url = replacement[1].get_absolute_url()

        auto_link = '<a href="%s">%s</a>' % (profile_url, to_replace)
        content = content.replace(to_replace, auto_link)

    return content
